Biometric authentication is a technique which provides user identity verification using biometric features such as fingerprints, the face, the iris, voiceprints, handwriting, etc. As compared with user identity verification based upon the user's memory such as a secret identification code, password, etc., in principle, it is difficult to crack biometric authentication by spoofing (i.e., an unauthorized user using a false identity). Accordingly, there has been more interest in biometric authentication as a technique which provides high security.
The multi-biometric technique is a technique which uses a combination of multiple biometric authentication items such as fingerprint authentication and face authentication, etc. By adjusting the combination, the ease of use may be improved or the security level may be raised. With an arrangement in which the user identity is verified if at least one of multiple authentication items is successful, authentication may be performed using a different authentication item even if fingerprint authentication may not be performed due to a situation in which the user's finger has been injured, etc., thereby improving the ease of use. An arrangement in which the user identity is verified only if all the multiple authentication items are successful provides an extremely high security level. Thus, such an arrangement may be applied to an access control operation for highly classified information, and so forth.
The user's hand is highly suitable for acquiring biometric information. Various authentication methods such as fingerprint authentication, vein authentication, hand outline authentication, etc., have already been implemented. Using a combination of such authentication methods, multi-biometric authentication is easily realized, which has the potential to improve authentication convenience or improve authentication precision.
Japanese Laid-open Patent Publication No. 2006-65400, Japanese Laid-open Patent Publication No. 2006-285487, Japanese Laid-open Patent Publication No. 2004-139611, Japanese Laid-open Patent Publication No. 2003-75892, Japanese Laid-open Patent Publication No. 2002-71578 and Japanese Laid-open Patent Publication No. 2006-153633 have been proposed.